<template>
  <div class="home-category">
    <!-- 1. 有数据显示 -->
    <template v-if="leftNavs.length > 0">
      <ul class="menu">
        <!-- 一级菜单 -->
        <li
          v-for="item in leftNavs"
          :key="item.id"
          @mouseenter="currCateId = item.id"
        >
          <router-link to="/">{{ item.name }}</router-link>
          <!-- <RouterLink to="/">{{ item }}</RouterLink> -->
          <!-- 二级菜单（前两个二级） -->
          <template v-if="item.children">
            <RouterLink v-for="sub in item.children" :key="sub.id" to="/">
              {{ sub.name }}
            </RouterLink>
          </template>
        </li>
      </ul>
      <!-- 鼠标hover之后显示=》推荐商品的弹层 -->
      <!-- 弹层 -->
      <div class="layer">
        <h4>分类推荐 <small>根据您的购买或浏览记录推荐</small></h4>
        <ul v-if="currGoods">
          <li v-for="good in currGoods" :key="good.id">
            <RouterLink :to="`/good/${good.id}`">
              <img :src="good.picture" alt="" />
              <div class="info">
                <p class="name ellipsis-2">{{ good.name }}</p>
                <p class="desc ellipsis">{{ good.desc }}</p>
                <p class="price"><i>¥</i>{{ good.price }}</p>
              </div>
            </RouterLink>
          </li>
        </ul>
      </div>
    </template>
    <!-- 2. 没有数据=》显示骨架屏结构 -->
    <template v-else>
      <ul class="menu">
        <li v-for="item in 9" :key="item">
          <!-- 占位 -->
          <!-- 一级分类名 -->
          <Skeleton
            :width="40"
            style="margin-right: 10px"
            :height="18"
            bg="rgba(255,255,255,.2)"
          />
          <!-- 两个二级分类名 -->
          <Skeleton
            :width="56"
            style="margin-right: 10px"
            :height="18"
            bg="rgba(255,255,255,.2)"
          />
          <Skeleton :width="56" :height="18" bg="rgba(255,255,255,.2)" />
        </li>
      </ul>
    </template>
  </div>
</template>

<script>
import { computed, ref } from 'vue'
import { useStore } from 'vuex'
export default {
  name: 'HomeCategory',
  setup () {
    const store = useStore()
    const leftNavs = computed(() => {
      return store.state.category.cateList.map(item => {
        return {
          id: item.id,
          name: item.name,
          children: item.children.slice(0, 2)
        }
      })
    })
    /**
     * 2. 需求:鼠标经过对应分类，右侧弹层显示当前分类推荐商品
     * 步骤：
     * 1. 注册经过事件=》获取当前分类下的推荐商品（item.goods）
     * 2. 在弹层中渲染推荐商品
     */
    const currCateId = ref('')
    // 获取当前分类下的推荐商品
    const currGoods = computed(() => {
      return store.state.category.cateList.find(item => item.id === currCateId.value)?.goods
    })
    return { leftNavs, currCateId, currGoods }
  }
}
</script>

<style scoped lang='less'>
.home-category {
  width: 250px;
  height: 500px;
  background: rgba(0, 0, 0, 0.8);
  position: relative;
  z-index: 99;
  .menu {
    li {
      padding-left: 40px;
      height: 55px;
      line-height: 55px;
      &:hover {
        background: @xtxColor;
      }
      a {
        margin-right: 4px;
        color: #fff;
        &:first-child {
          font-size: 16px;
        }
      }
    }
  }
  // 弹层默认不显示
  .layer {
    width: 990px;
    height: 500px;
    background: rgba(255, 255, 255, 0.8);
    position: absolute;
    left: 250px;
    top: 0;
    display: none;
    padding: 0 15px;
    h4 {
      font-size: 20px;
      font-weight: normal;
      line-height: 80px;
      small {
        font-size: 16px;
        color: #666;
      }
    }
    ul {
      display: flex;
      flex-wrap: wrap;
      li {
        width: 310px;
        height: 120px;
        margin-right: 15px;
        margin-bottom: 15px;
        border: 1px solid #eee;
        border-radius: 4px;
        background: #fff;
        &:nth-child(3n) {
          margin-right: 0;
        }
        a {
          display: flex;
          width: 100%;
          height: 100%;
          align-items: center;
          padding: 10px;
          &:hover {
            background: #e3f9f4;
          }
          img {
            width: 95px;
            height: 95px;
          }
          .info {
            padding-left: 10px;
            line-height: 24px;
            overflow: hidden;
            .name {
              font-size: 16px;
              color: #666;
            }
            .desc {
              color: #999;
            }
            .price {
              font-size: 22px;
              color: @priceColor;
              i {
                font-size: 16px;
              }
            }
          }
        }
      }
    }
  }
  // 显示弹层
  &:hover {
    .layer {
      display: block;
    }
  }
}
</style>
